Hello Bray Welcome to the WindowsForums!
The main problem you are going to continue to run into as far as Windows 8 is concerned is that there are no Win 8 drivers to find for that particular model series! That was the immediate disadvantage of not looking up the drivers available before making any OS change which a growing number of people are finding out unfortunately the hard way.
I can't put it any other way as far as being straight forward with the facts. When each new version of Windows arrives only the latest new OEM machines will see support. Those will come with the latest version preinstalled. For upgrading anything with a previous version of Windows on it looking to see if the newer version's drivers are available is the first step.
The reason for the "best driver already installed" message is due to that being the only latest version of the driver written for Windows 7 which came preinstalled. Unlike the closeness in compatibility allowing a much smoother upgrade from Vista to 7 on the same hardwares where 7 did see much more support from the start Windows 8 will be another slow boat.
For Vista many 3rd party sources took a year if not longer to finally release drivers for things like expansion cards and other devices once Vista had been out for some time. They were more or less forced to do that since they still wanted to be able to sell the same product lines to Vista users. Likewise this sounds all too familiar with Win 8 too.
The Golden Rule to follow first for anyone planning to upgrade the version of Windows on any machine OEM or custom built is to first to see what support is acutally out there before making any changes. I still havien't been finding drivers for 8 for the hardwares here other then the video card. For the AMD/ATI example that would be the Catalyst 12.10 now available. For the Creative X-Fi XtremeGamer model sound card Creative still only has a beta driver listed at their support site and that listed as Late Dec. 2012!
Besides being driver related you also have to start looking at the registry as having a problem following the upgrade where the Code 39 is most commonly caused from and not just on Windows 8 either. The instructions besides a restore point since you likely don't have one quite yet is looking over the instructions for how to go about correcting the actual problem is found at How To Fix Code 39 Errors
The page there will have a few links for other pages for individual sets of instructions for each step you would need to take. Hopefully this will clear the problem up for you after the first try.